The present invention relates to an audit monitoring and product drop system for use in retrofitting existing vending machines and more particularly to an audit monitoring and product drop system which provides for the entry of transaction data into a memory for subsequent retrieval only if a product drop is sensed by the product drop sensor and to a method of operating a vending machine having a product drop system.
Prior art audit monitoring systems are well known in the art and audit monitoring systems for retrofitting existing vending machines are known in the art such as disclosed in U.S. Pat. No. 5,924,081 and U.S. Pat. No. 5,442,562. However, audit monitoring systems for retrofitting existing vending machines do not have the capability to retrofit existing vending machines with a product drop sensor. Product drop systems, for use in OEM manufactured vending machines are disclosed in U.S. Pat. No. 6,384,402 and U.S. Pat. No. 4,252,250 and are also known in the art, but are not readily usable to retrofit existing vending machines. With the vending of products of various configurations, a product drop system including a product drop sensor is becoming more important due to the possibility of miss-vends of a selected product where the selected product dispensing mechanism is actuated, but the selected product is not dispensed.
The present invention overcomes the problems associated with the prior art by providing a new and improved audit monitoring system having a product drop sensor which is capable of retrofitting existing vending machines. The product drop sensor ensures that a product is dispensed before dispensing change and storing transaction data such as products dispensed, total funds received, funds in the cash box and change available to be dispensed.